Dexmedetomidine Infusion versus Fentanyl for Analgesia and Prevention of Emergence Agitation in Children Undergoing Tonsillectomy and Adenoidectomy

Abstract

Adenotonsillectomy is one of the most common surgical procedures performed in children. The presence of obstructive symptoms is the primary indication for adenotonsillectomy. Pain is “An unpleasant sensory and emotional experience associated with actual or potential tissue damage.” acute pain is primarily due to nociception. Postoperative pain is one of the types of acute pain and can be somatic or visceral pain. Somatic pain is due to nociceptive input arising from skin, subcutaneous tissues and mucous membranes. It is well-localized, sharp, pricking, throbbing or burning. Postoperative pain can be severe after adenotonsillectomy. Moderate to severe acute pain, regardless of its site, can affect nearly every organ function and may adversely influence postoperative morbidity and mortality. Acute pain is typically associated with neuroendocrine stress response that is proportional to pain intensity Pain measurement is done by two methods: (1) Type I methods: (objective): done by the physician. It includes the following: Physiological indices, neuro-pharmacological, neurological, and behavioral. 1. Objective pain score. 2. Modified Objective Pain Score. (2) Type II methods (subjective): needs patient’s cooperation. It includes either: *Single dimension methods: Verbal rating scale, FLACC scale, Visual analogue scale, Wong-Baker Faces scale. *Multi-dimensional methods: • Mc Gill pain Questionnaire, Dartmouth pain Questionnaire, West Haven-Yale pain Questionnaire. Dexmedetomidine one of the most recently released IV anesthetic, it is a highly selective α2-adrenergic agonist that produces sedation, hypnosis, analgesia, sympatholysis, anxiolysis. Its primary action is as an agonist on α2 receptors in the locus caeruleus. It is a safe drug with minimal effect on respiratory and cardiovascular systems when used as infusion and by omitting the loading dose in susceptible patients. It is used in the ICU and in anesthesia with great safety margins. Emergence agitation is a disturbance in a child’s awareness and attention to his/her environment with disorientation and perceptual alterations including hypersensitivity to stimuli and hyperactive motor behavior in the immediate post anesthesia period. It usually occurs within the first 30 min of recovery from anesthesia. Multiple factors have been suggested to play a potential role in initiation of emergence agitation: it may be anesthesia related factors as (rapid emergence, or due to intrinsic characteristics of an anesthetic as emergence agitation occurs more often after sevoflurane, desflurane than after halothane anesthesia) or it may be surgery related factors as (pain, surgery type), indeed it may be patients related factors as (age, preoperative anxiety, temperament), at last it may be due to adjunct medications e.g.: Atropine.